Vibrator



Patented Mar. 11, 1924.

UNITED STATES P. KRAUSE, OF CHICAGO, ILLINOIS, ASSIGNOR TO MUMFORD MOLDING MACHINE COMPANY, A CORPORATION OF NEW JERSEY.

vrsnarn.

Application filed January 4, 1919. Serial No. 269,579.

To all whom. it may 0012mm:

Be it known that I, WILLIAM P. KRAUsE, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Vibrators, of which the following is a specification.

This invention relates to improvements in vibrators, and has for its object to provide a new and improved vibrator especially adapted for use in molding machinery, and in molding operations.

In my vibrator I provide a reciprocating piston. in which is located a central duct of such size as to constitute in efl'ect a reservoir, which, in conjunction with the arrangement of coacting ducts, etc., ensures almost an instantaneous supply of fluid pressure to either end of the vibrator cylinder, thereby eliminating the delay present in present day devices and permitting greater rapidity of reciprocation of the vibrator piston.

Another object of my invention is the provision of a small exhaust port, or escape vent, to permit the escape of operating fluid which may leak past the main control valve, which leakage in present-day vibrators results in moving the piston to inoperative position and stalling of the same.

These and other objects of the invention will be more fully'set forth and described in the following specification, and shown in the accompanying drawing, in which-.-

Figure 1 is a vertical longitudinal section through the vibrator, the plugs or caps at the end thereof being shown in elevation;

Fig. 2 is a vertical transverse-section, taken on the line 22 of Fig. 1;

gig. 3 is a side elevation of the piston; an

Fig. 4 is a transverse vertical section, taken on the line 4-4 of Fig. 1.

Like numerals refer to like elements throughout the drawings, in which 10 indicates generally the vibrator cylinder, internally threaded at each end to accommodate the plug 11 at one end and the cap 12 at the other end. The cap is provided with an apertured projecting flange 12 intended to be attached by a bolt, or the like, tothe pattern frame of a vibrator, or to whatever mechanism it is desired to vibrate. Adjacent each end of the cylinder in the interior thereof is provided a recess 10. The cylinder is further provided with an enlarged inlet port 10 and with exhaust ports 10 and 10". A small vent, or escape port, 10 is also provided in the cylinder. for a purpose to be hereinafter described. 4

Reciprocably mounted in the cylinder is the vibrator piston 13 closely fitting the interior of the cylinder, as is customary in such devices, to permit-the operation of the same without a piston ring. The piston is provided with bosses or projections 13, 13 at its ends, as shown in Fig. 3 for example, and is further provided with a central peripheral groove 13 and with smaller peripheral grooves 13 and 13 adjacent the ends of the piston. An enlarged central duct or conduit 13. is provided in the piston, as shown in Figs. 1, 2, and 4, for example, this aperture being preferably formed by drilling, and the open end resulting from such drilling being sealed by the threaded plug 13 ,'see Fig. 1.

Communicating ducts13, 13 lead to the grooves 13 13, respectively, from the central aperture 13 the first-named duct being made smaller than the duct 13 for a purpose to be hereinafter described, this feature notbeing a part of my invention, but being covered in a copending application of Philetus W. Gates, Serial No. 269,582, filed January 4, 1919. A cross duct 13 leads from, the central aperture 13 to the central peripheral groove 13, as shown in Figs. 1 to 3, respectively.

A helical spring 14 fits around the boss 13 of the piston, and extends between the end thereof and the cap 12, as shown in Fig. 1. The boss 13 being smaller than the boss 13 ensures proper assembling of the spring and piston, as is necessary for proper functioning of the vibrator.

In the operation of my device, when the main control valvenot shown-is moved to open position fluid under pressure passes through the supply pipe A, Fig. 1, through duct 10", around groove 13", and to central duct 13 through cross duct 13% With the piston in the position shown in Fig. 1 the operating fluid will pass from the central duct 13 through cross duct 13 to peripheral groove 13, which is in communication with the recess 10. This permits flow of the fluid into the right hand end of the cylinder, as viewed in Fig. 1, and results in til rapidshiftin' of the piston from the position shown t erein to the opposite end of the cylinder against the action of the spring 14. It will be obvious that as soon as the groove 13 has moved a small distance from the position shown in Fig. 1 communication with recess will be cut ofl','and no further air will be supplied for movement unroove 13 communicates with'recess 10* at t e opposite end of the cylinder. Just prior to or about the time the communication is effected between the groove 13 and recess 10* exhaust at the other end of the c linder takes place through uncovering of the exhaust port 10 by the body of the piston. As the piston impacts against the cap 12, due to the movement described above,-

the operating fluid flowing from the central duct 18 to peripheral groove 13, and from thence into the end of. the cylinder, will force the piston rapidly back in a movement reverse. to that described above. This reverse movement is enhaiieed and accelerated by the, action of the compressed spring 14. The cross duct 13 being considerably smaller than the duct'13 the return movement, even as assisted by the coil spring 14, is under considerably less pressure, and consequently the impact resulting from the re verse movement is considerably less than that resulting from the first-described movement, so that there is an unbalanced vibration, which makes for a more eflicient functioning of the device. This. feature,'as explained above, does not form a portion of my invention.

Inasmuch as many of the control valves used with these devices permit a certain amount of leakage of the operating fluid, there is in many instances a certain flow, even with the valve in closed position, which flow often results in the piston being moved from the position shown in Fig. 1a suflicient distance against the action of the spring 14 to cut ofi duct 13 prior to registeringof groove 13 with recess 10, whereby the vibrator is maintained in inoperative or stalled position, as it is termed, so that when the pressure is turned on fully no functioning of the vibrator results. To obviate this difliculty I have provided the small vent or duct 10 in communication with the central peripheral groove 13, as shown in Fig. 1 which provides an outlet for any such leakage.

It will be obvious from the above description that by the provision of the central enlarged duct 13, which is in efi'ect a reservoir, a constant supply of air is obtained in the peripheral grooves 13 and 13 ready for immediate flow to the end of the cylinder, the balance of the distance the operating fluid is required to travel being so small as to make the effect of the fluid pressure practically instantaneous, resulting in greatly increased speed of the vibrator. This advantage over present-day vibrators, wherein relativel considerable travel of the operating flui is required from the source of supply to the ends of the cylinder, is the result of my construction. This advantage will be obvious to those skilled in the art, especially where vibrators are used, for example, for molding machines, where a high vibration, resulting in small amplitude and great efficiency is required to obtain the proper parting of the pattern from the sand without jarring the sand from. its molded position.

It will be obvious that my invention is susceptible of many modifications and improvements; and I do not therefore wish to be restricted to the form shown and described, except as defined in the appended claims.

I claim 1. 'A Vibrator comprising a cylinder, a piston reciprocably mounted therein to impact at each end of said cylinder, said cylinder being provided with a fluid supply inlet and said piston being provided with a pcripheral groove and an interiorly located duct, means for conveying operating fluid .from said groove to said duct, and means to convey said operating fluid from said duct to either end of said cylinder, said lastnamed means comprising cross ducts, said piston being further provided with peripheral grooves at the emergence of said cross ducts.

2. A vibrator comprising a cylinder, a piston reciprocably mounted therein to impact at eachend of said cylinder, said cylinder being provided with a fluid supply inlet and said piston being provided with peripheral groove and an interiorly located duct, means for conveying operating fluid from said groove to said duct. and means to conve said operating fluid from said duct to eit er end of said cylinder, said last-named means-comprising cross ducts, said piston being further provided with peripheral grooves at the emergence of said cross ducts, said cylinder being recessed interiorly-adjacent its ends, said recesses being communicable with said last-named peripheral grooves.

In testimony whereof, I have subscribed 

